An example of a conventional vehicle driving support device includes the technology described in Japanese Kokai Patent Application No. 2005-41459. With that technology, when an obstacle is detected on one of the sides of a vehicle, if the distance from a lane dividing line to the vehicle is less than a prescribed distance, a yaw moment is produced so that the distance from the lane dividing line to the vehicle will be changed so that it equals at least the prescribed distance. Thus the distance between the obstacle and the vehicle is prevented from becoming smaller than the prescribed distance.